1. Field of the Invention
The present invention relates to a flexible printed wiring board having a connector connecting portion.
2. Description of the Related Art
FIG. 11 shows an exemplary conventional flexible printed wiring board. This flexible printed wiring board 1 has a connector connecting portion 2 at a leading end thereof. A plurality of conductor patterns 3 are exposed in the connector connecting portion 2, and to ensure hardness and prevent oxidization, the exposed portion is subjected to multilayer electrolytic plating. Accordingly, plated leads 4 are provided in a manner extending from leading ends of the conductor patterns 3 to a leading end face of the flexible printed wiring board 1 in a direction in which the flexible printed wiring board 1 is inserted, so that the conductor patterns 3 and plating electrodes can be electrically connected to each other.
In many cases, the connector connecting portion 2 is inserted obliquely (obliquely in plan view) to a normal insertion direction into a connector 5 that is relatively small in width. In such cases, the plated leads 4 located outermost in the width direction of the connector connecting portion 2 slide in contact with the connector terminals in the connector 5 obliquely across the connector terminals.
Here, the plated leads 4 have low peel strength in a direction perpendicular to the direction in which they extend, and hence repeated insertion and extraction of the connector connecting portion 2 into and from the connector 5 may cause the plated leads 4 to peel off, resulting in electrically poor connection, leakage, shorting, or the like.
Accordingly, there has been proposed a technique according to which concaves are provided in leading end faces of plated leads of a flexible printed wiring board so as to inhibit the plated leads from coming into contact with connector terminals or the like (Japanese Laid-Open Patent Publication (Kokai) No. H05-165048). Also, there has been proposed a technique according to which in a multilayer printed wiring board, plated leads are disposed in an internal layer and sandwiched between upper and lower base material layers so as to inhibit the plated leads from coming into contact with connector terminals or the like (Japanese Laid-Open Patent Publication (Kokai) No. H06-196869).
However, if concaves are provided in leading end faces of plated leads of a flexible printed wiring board as with the technique described in Japanese Laid-Open Patent Publication (Kokai) No. H05-165048, the overall length of the flexible printed wiring board will increase correspondingly.
Also, the technique described in Japanese Laid-Open Patent Publication (Kokai) No. H06-196869 cannot be applied to a one-sided flexible printed wiring board or a double-sided flexible printed wiring board.